Hi, i'll just post the full list of edits that need to be completed, just in case someone stumbles on this thread in the future.
#i did the following not through ssh, but with a physical keyboard
#enable root user
sudo passwd root
#logout of the user pi
logout
#Log back in as root
#Rename user pi
usermod -l newname pi
#Rename the user's home directory
usermod -m -d /home/newname newname
#Rename group pi
groupmod --new-name newname pi
#Now logout and log back in as newname
#Disable password prompt for sudo
cd /etc/sudoers.d/
sudo mv 010_pi-nopasswd 010_newname-nopasswd
sudo nano 010_Name-nopasswd
# edit the name pi to newname
#Double check newname has sudo privileges
sudo visudo
#Disable Root
sudo passwd -l root
#fix the getty autologin username or else stuck at boot
sudo nano /etc/systemd/system/autologin@.service
#search for the following line
ExecStart=-/sbin/agetty --autologin pi --noclear %I $TERM.
#smb.conf has pi user in the share definitions
sudo nano /etc/samba/smb.conf
#Change the es_systems.cfg folder paths
cd /opt/retropie/configs/all/emulationstation/
cp es_systems.cfg es_systems.cfg.pi.bak
sudo nano es_systems.cfg
#Folder configs and everything below /opt/retropie/configs/
sudo chown -R newname:newname /opt/retropie/configs/
#Paths for game image files also need editing
#Look in /opt/retropie/configs/all/emulationstation/gamelists/
#check fstab if you have mounted anything
sudo nano /etc/fstab
# If you installed Drastic all the containing files of /opt/retropie/emulators/drastic/
sudo chown -R Name:Name /opt/retropie/emulators/drastic/*
